‘Direct strike’

It said that the hospital was well known locally and had been hit by a direct air strike on Wednesday.

“We condemn the destruction of the al-Quds hospital, depriving people of essential healthcare,” the charity added.

An activist at the scene, named as Zuhair, told the BBC that buildings around the hospital were also hit.

“It was an air strike by two rockets, heavy rockets from [a] Russian air strike,” he said.

“Near the hospital one building on five floors just crumbled and just crashed down and we don’t know how many dead will be under these ruins.”

Image captionThe air strikes threaten to sink the Geneva peace talks

The civil defence agency, which is staffed by volunteers, said the hospital and surrounding buildings were hit by four consecutive air strikes.

Rami Abdurahman, head of the monitoring group the Syrian Observatory for Human Rights, named the paediatrician killed as Mohammed Wasim Moaz, 36.

He told the BBC that Mr Moaz was the last paediatrician in the rebel-held part of Aleppo and another was to be sent on Thursday to take his place.

The Observatory said rebel rocket fire on government-held areas on Thursday had killed 14 civilians while attacks by pro-government forces on rebel neighbourhoods had killed at least 20 people.

Analysis by Jim Muir, BBC News, Beirut

The two-month-old “cessation of hostilities”, which brought at least a relative lull to some parts of Syria, is indeed “hanging by a thread” as the UN mediator Staffan de Mistura put it.

One of the reasons why it is now at death’s door was reflected in the fact that from the outset it was not called a ceasefire or even a truce, because several factions were excluded, including not just the Islamic State militants but also the al-Qaeda-linked Nusra Front.

Nusra fighters are present in almost all combat zones, and are mixed up with other groups such as Ahrar al-Sham that Russia is now pressing to have added to the international terror list.

That has meant that hostilities have continued and intensified in many areas, with the government able to claim its attacks are legitimate.

Now state forces are reported to be building up in Aleppo as violence escalates there, raising fears that a long and costly all-out battle for the contested city may be looming.

That would put paid both to the lull and to the Geneva peace talks, prompting the UN envoy to urge the US, Russians and others to press their clients on the ground to ease off, so that stalled negotiations have a chance of resuming.

Syrian state news made no mention of the hospital attack but also said that rebel shelling had killed at least 14 civilians in government-held areas in the north of the city.

Over the past week, more than 100 civilians have been killed in renewed bombardment by both rebel and government forces in Syria’s largest city, according to the UK-based Observatory.

Speaking on Wednesday after briefing the UN Security Council on the peace process, the envoy to Syria, Staffan de Mistura, warned that the fragile cessation of hostilities agreed in February could collapse “at any time”.

He said that over the past 48 hours an average of one Syrian had been killed every 25 minutes and one wounded every 13 minutes.

For the peace talks in Geneva to succeed, he added, hostilities would need to be reduced to the levels immediately following the February agreement.

Calling on the US and Russia to co-operate, Mr de Mistura said the legacies of both President Barack Obama and President Vladimir Putin were linked to the success of the peace process in Syria.

More than 270,000 people have been killed since Syria’s bitter civil war conflict erupted in 2011 and millions have been forced to flee.